Spatial Attribute Appender
Transfer attributes from a source layer to a target layer by spatial relationship (intersect/touch or nearest feature), with automatic field creation, optional Manual Field Mapping support, and undoable edits.
Spatial Attribute Transfer copies attributes (fields and values) from a source vector layer onto a target vector layer based on a spatial relationship. Two matching modes are available: Intersect/Touch and Nearest Feature (with an optional maximum search distance, powered by QgsSpatialIndex). By default, all matching fields are transferred automatically and missing fields are created in the target layer, preserving type, length and precision. An optional Field Mapping table lets you take manual control instead: Auto Match to pre-fill suggestions, then freely edit which source field goes to which target field, retarget a value to a differently named field, or create a brand-new target field on the fly. Geometries are never modified, and all changes happen inside an edit session grouped into a single undo command, so one Ctrl+Z reverts the whole transfer. Supports Point, LineString, MultiLineString, Polygon and MultiPolygon layers, and handles differing CRSs via on-the-fly reprojection.